Cycle wheel suspension assembly having gas pistons with unequal gas piston areas

Abstract

A suspension assembly for a cycle having improved stability includes a steering fork having a steering axis, a first arm, and a second arm, each of the first arm and the second arm having a fixed pivot and a shock pivot, the space between the first arm and the second arm defining a wheel opening. A shock link has a shock link fixed pivot and a shock link floating pivot. A shock absorber has a shock gas spring comprising a shock spring body a shock gas piston having a first gas piston area, a spring unit has a spring gas spring comprising a spring body and a spring gas piston having a second gas piston area. The first gas piston area is not equal to the second gas piston area. A mechanical trail distance increases as the suspension assembly compresses relative to a fully extended state.

What is claimed: 
     
       1. A suspension assembly for a cycle, the suspension assembly comprising:
 a steering fork, the steering fork having a steering axis, a first arm, and a second arm, each of the first arm and the second arm having a first end and a second end; 
 a shock absorber having a damper body and shock gas spring comprising a shock spring body and a shock gas piston having a first gas piston area, the shock spring body being sequentially arranged along a substantially common central axis with the damper body, the shock absorber including a first shock mount and a second shock mount, the first shock mount being connected to the first arm, the second shock mount being pivotably connected to a shock link, and the shock absorber being located on the first arm; 
 a spring unit, having a spring gas spring comprising a spring body and a spring gas piston having a second gas piston area, a first spring mount and a second spring mount, the first spring mount being connected to the second arm, the second spring mount being pivotably connected to a spring link, and the spring unit being substantially located on the second arm; 
 wherein the first gas piston area and the second gas piston area are unequal, and 
 wherein, a mechanical trail distance, which is a distance between a ground contact point of a wheel connected to the wheel mount and the steering axis, increases as the suspension assembly compresses relative to a fully extended state. 
 
     
     
       2. The suspension assembly of  claim 1 , further comprising:
 a first arm fixed pivot, a first arm shock pivot, and a first arm control pivot, a space between the first arm and the second arm forming a wheel opening; 
 the shock link, the shock link having a shock link fixed pivot and a shock link floating pivot spaced apart from one another, the shock link being pivotably connected to the first arm fixed pivot at the shock link fixed pivot such that the shock link is rotatable about the shock link fixed pivot and the shock link fixed pivot remains in a fixed location relative to the first arm while the shock link floating pivot is movable relative to the first arm; 
 a wheel carrier, the wheel carrier having a wheel carrier first pivot and a wheel carrier second pivot spaced apart from one another along a length of the wheel carrier, and a wheel mount that is adapted to be connected to a wheel, the wheel carrier first pivot being pivotably connected to the shock link floating pivot so that the wheel carrier second pivot is rotatable about the wheel carrier first pivot relative to the shock link floating pivot; and 
 a control link, the control link including a control link floating pivot and a control link fixed pivot, the control link floating pivot being pivotably connected to the wheel carrier second pivot, and the control link fixed pivot being pivotably connected to the first arm control pivot such that the control link floating pivot is rotatable about the control link fixed pivot, which remains in a fixed location relative to the first arm control pivot. 
 
     
     
       3. The suspension assembly of  claim 2 , wherein the damper body is located between the shock spring body and the second shock mount along the common central axis. 
     
     
       4. The suspension assembly of  claim 2 , wherein the second gas piston area is larger than the first gas piston area. 
     
     
       5. The suspension assembly of  claim 2 , wherein the suspension assembly is a multi-link assembly. 
     
     
       6. The suspension assembly of  claim 2 , wherein the shock gas piston has a greater radial cross-sectional area than a damper piston. 
     
     
       7. The suspension assembly of  claim 2 , wherein the shock spring body is located between the damper body and the second shock mount along the common central axis. 
     
     
       8. The suspension assembly of  claim 1 , wherein the central axis of the shock spring body and a central axis of the damper body are arranged so that the central axis of the shock spring body and the central axis of the damper body are offset from one another by a maximum of 100% of the outside diameter of an inshaft of the inline shock absorber.